Plastic lens barrel, imaging lens module and electronic device

ABSTRACT

A plastic lens barrel includes an object-end portion, an image-end portion and a tube portion. The object-end portion has an object-end outer surface, an object-end opening and an object-end inner surface, wherein one end of the object-end inner surface is connected to the object-end outer surface and surrounds the object-end opening. The image-end portion has an image-end outer surface and an image-end opening. The tube portion connected object-end portion and the image-end portion, and includes a plurality of tube inner surfaces. At least one of the tube inner surfaces and the object-end inner surface includes a plurality of annular convex structures. Each of the annular convex structures surrounds a central axis of the plastic lens barrel. A cross-sectional plane of each annular convex structure passing through the central axis includes a peak point and two valley point.

RELATED APPLICATIONS

The present application is a continuation of the application Ser. No.16/655,485, filed Oct. 17, 2019, which claims priority to TaiwanApplication Serial Number 108102307, filed Jan. 21, 2019, which isherein incorporated by reference.

BACKGROUND Technical Field

The present disclosure relates to a plastic lens barrel and an imaginglens module. More particularly, the present disclosure relates to aplastic lens barrel and an imaging lens module applicable to portableelectronic devices.

Description of Related Art

In recent years, the portable electronic devices have been developedrapidly, such as smart devices, tablets and so on. These portableelectronic devices have been full of daily lives of modern people, andthe camera module loaded on the portable electronic devices thrives onit. The demand for quality of the camera module increases along with theadvances in technology. Therefore, the camera module needs to beimproved not only on the quality of the optical design but manufacturingassembling precision.

FIG. 10 is a schematic view of an imaging lens module 10 applied tocamera module in the conventional art. In FIG. 10 , the imaging lensmodule 10 includes a lens barrel 11 and a plurality of optical elements12 (such as lens elements, light shielding sheets), wherein the opticalelements 12 are disposed in the lens barrel 11. The lens barrel 11 ismade by an injection molding, and an inner surface thereof is arrangedwith a plurality of stepped structures 11 a. However, each of thestepped structures 11 a does not have obvious peak point and valleypoints, the positions 11 b, and 11 c thereof projecting on the opticalaxis overlap to each other. Hence, the image would be affected by thestray light, so as to affect the image quality.

SUMMARY

According to one aspect of the present disclosure, a plastic lens barrelincludes an object-end portion, an image-end portion, and a tubeportion. The object-end portion has an object-end outer surface, anobject-end opening, and an object-end inner surface, wherein one end ofthe object-end inner surface is connected to the object-end outersurface and surrounds the object-end opening. The image-end portion hasan image-end outer surface and an image-end opening. The tube portionconnects the object-end portion and the image-end portion, and includesa plurality of tube inner surfaces, wherein at least one of the tubeinner surfaces and the object-end inner surface includes a plurality ofannular convex structures, each of the annular convex structuressurrounds a central axis of the plastic lens barrel, and across-sectional plane of each of the annular convex structures passingthrough the central axis includes a peak point and two valley points.The peak point is a closest point to the central axis on each of theannular convex structures. Projecting positions of the two valley pointson the central axis are located on two sides of a projecting position ofthe peak point on the central axis, and the projecting positions of thetwo valley points on the central axis do not overlap with the projectingposition of the peak point on the central axis.

According to another aspect of the present disclosure, an imaging lensmodule includes the plastic lens barrel of the aforementioned aspect andan optical lens assembly, wherein the optical lens assembly is disposedin the plastic lens barrel.

According to another aspect of the present disclosure, an electronicdevice includes the imaging lens module of the aforementioned aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be more fully understood by reading thefollowing detailed description of the embodiment, with reference made tothe accompanying drawings as follows:

FIG. 1A is a schematic view of an imaging lens module according to the1st embodiment of the present disclosure.

FIG. 1B is an exploded view of the imaging lens module according to the1st embodiment in FIG. 1A.

FIG. 1C is a planar cross-sectional view of a plastic lens barrelaccording to the 1st embodiment in FIG. 1A.

FIG. 1D is a three-dimensional view of the plastic lens barrel accordingto the 1st embodiment in FIG. 1A.

FIG. 1E is a schematic view of parameters d, and D according to the 1stembodiment.

FIG. 1F is a schematic view of molds in the manufacturing process of theplastic lens barrel according to the 1st embodiment.

FIG. 2A is a schematic view of an imaging lens module according to the2nd embodiment of the present disclosure.

FIG. 2B is a three-dimensional view of the plastic lens barrel accordingto the 2nd embodiment in FIG. 2A.

FIG. 2C is a planar cross-sectional view of the plastic lens barrelaccording to the 2nd embodiment in FIG. 2A.

FIG. 3A is a schematic view of an imaging lens module according to the3rd embodiment of the present disclosure.

FIG. 3B is a three-dimensional view of the plastic lens barrel accordingto the 3rd embodiment in FIG. 3A.

FIG. 3C is a planar cross-sectional view of the plastic lens barrelaccording to the 3rd embodiment in FIG. 3A.

FIG. 4A is a schematic view of an imaging lens module according to the4th embodiment of the present disclosure.

FIG. 4B is a planar cross-sectional view of the plastic lens barrelaccording to the 4th embodiment in FIG. 4A.

FIG. 5A is a schematic view of an imaging lens module according to the5th embodiment of the present disclosure.

FIG. 5B is a planar cross-sectional view of a plastic lens barrelaccording to the 5th embodiment in FIG. 5A.

FIG. 6A is a schematic view of an appearance of an electronic deviceaccording to the 6th embodiment of the present disclosure.

FIG. 6B is another schematic view of the appearance of the electronicdevice according to the 6th embodiment in FIG. 6A.

FIG. 6C is a schematic view of elements of the electronic deviceaccording to the 6th embodiment in FIG. 6A.

FIG. 6D is a block diagram of the electronic device according to the 6thembodiment in FIG. 6A.

FIG. 7 is a schematic view of an electronic device according to the 7thembodiment of the present disclosure.

FIG. 8 is a schematic view of an electronic device according to the 8thembodiment of the present disclosure.

FIG. 9 is a schematic view of an electronic device according to the 9thembodiment of the present disclosure.

FIG. 10 is a schematic view of an imaging lens module applied to cameramodule in the conventional art.

DETAILED DESCRIPTION

The present disclosure provides a plastic lens barrel, including anobject-end portion, an image-end portion, and a tube portion. Theobject-end portion has an object-end outer surface, an object-endopening, and an object-end inner surface, wherein one end of theobject-end inner surface is connected to the object-end outer surfaceand surrounds the object-end opening. The image-end portion has animage-end outer surface and an image-end opening. The tube portionconnects the object-end portion and the image-end portion, and includesa plurality of tube inner surfaces, wherein at least one of the tubeinner surfaces and the object-end inner surface includes a plurality ofannular convex structures, each of the annular convex structuressurrounds a central axis of the plastic lens barrel, and across-sectional plane of each of the annular convex structures passingthrough the central axis includes a peak point and two valley points.The peak point is a closest point to the central axis on each of theannular convex structures. Projecting positions of the two valley pointson the central axis are located on two sides of a projecting position ofthe peak point on the central axis, and the projecting positions of thetwo valley points on the central axis do not overlap with the projectingposition of the peak point on the central axis. Therefore, an elasticdrafting structure with reversed hook-shaped can be formed. It isfavorable for obtaining an appearance of injection molding which hasbeen considered to be difficult to form by utilizing the elastic plasticwhich has just been formed via injection molding. Moreover, it isfavorable for achieving an ideal improvement in the potential surfacereflection by arranging the tube inner surfaces of the plastic lensbarrel with reversed hook-shaped without adding more complex molddesigns and correspondingly expensive mold costs, so as to transfer theinevitable reflection of the stray light of the tube inner surfaces intothe reversed hook structure which can be considered as entering into thelight trap so as to eliminate the original stray light projecting on theimage surface.

The annular convex structures and the plastic lens barrel can beintegrally formed. Therefore, it is favorable for reducing the cost ofoptimizing design of the plastic lens barrel by more easily applying tothe plastic lens barrel with the countermeasure for eliminating straylight of the tube inner surfaces.

Each of the projecting positions of the peak points on the central axisdoes not overlap with each of the projecting positions of the valleypoints on the central axis. Therefore, it is favorable for making thelight trap structure more stereoscopic without being limited by draftingrequirements of the conventional injection molding.

Projecting positions of the two valley points on an axis vertical to thecentral axis do not overlap with projecting position of the peak pointon the axis vertical to the central axis. Therefore, it is favorable forsignificantly improving the success rate of injection molding productsand the quality of mass production by greatly reducing the collision andinterference in the drafting step between the plastic lens barrel andthe corresponding mold.

A distance between the projecting position of one of the two valleypoints on the central axis and the projecting position of the peak pointon the central axis is different from a distance between the projectingposition of the other one of the two valley points on the central axisand the projecting position of the peak point on the central axis.Therefore, it is favorable for adjusting to the appropriate structure inresponse to the conditions of injection molding by designing the annularconvex structures as a steep slope structure so as to increase thefeasibility of mass production.

The two valley points are a first valley point and a second valleypoint, respectively, and a distance between a projecting position of thefirst valley point on the central axis and the projecting position ofthe peak point on the central axis is larger than a distance between aprojecting position of the second valley point on the central axis andthe projecting position of the peak point on the central axis.Therefore, it is favorable for obtaining the depth of light trap and therequirement of elastic drafting structure being considered in a draftingstage by maintaining different distances.

When the distance between the projecting position of the first valleypoint on the central axis and the projecting position of the peak pointon the central axis is DG1, and the distance between the projectingposition of the second valley point on the central axis and theprojecting position of the peak point on the central axis is DG2, thefollowing condition is satisfied: 1.1<DG1/DG2<25.0. Therefore, thearrangement of light trap can become more ideal and the plasticstructure of elastic drafting would not be destroyed. Furthermore, thefollowing condition can be satisfied: 1.8<DG1/DG2<17.0. Therefore, it isfavorable for obtaining more adjustable margin from controlling thevariables by the molding mold.

Each of the annular convex structures can have a smooth surface.Therefore, it is favorable for increasing manufacturing speed byreducing the processing steps of the surface treatment.

When a maximum opening diameter of the annular convex structures is D, aminimum opening diameter of the annular convex structures is d, and anelastic drafting ratio of the annular convex structures is EDR, thefollowing condition is satisfied: 0%<EDR<12%, whereinEDR=[(D−d)/D]×100%. Therefore, the function of the elastic draftingstructure can be more ideally. Furthermore, the following condition canbe satisfied: 0%<EDR<8%. Therefore, it is favorable for avoidingunexpected destruction in the drafting stage which would result inlosing functions of the light traps. In detail, the value of EDR can bechanged to a feasible proportion according to the arrangement of theplastic lens barrel. The non-closed annular convex structure, thenon-closed image-end inner surface or the non-closed tube inner surfaceswill change the feasible range of EDR, but is not limited thereto.

The two valley points of each of the annular convex structures arefarther from the central axis than the peak point of each of the annularconvex structures is thereto. Therefore, the appearance near the peakpoint would be sharper, so that it is not easy to appear tiny planes orgentle slopes, or the like, which would cause the annular convexstructure to illuminate after illumination and increase unnecessaryappearance of abnormalities.

The peak point of each of the annular convex structures is graduallyaway from the central axis from the object-end portion to the image-endportion or from the image-end portion to the object-end portion.Therefore, it is favorable for reducing the number of collisions thateach of the annular convex structures is subjected to during thedrafting, so as to improve the success rate.

In each of the annular convex structures, when a maximum distancebetween the projecting position of each of the valley points and theprojecting position of the peak point on the axis vertical to thecentral axis is HG, the following condition is satisfied: 0.002mm<HG<0.15 mm. Therefore, it is favorable for reducing the degree ofsurface reflection and being not easy to increase the failure rate whendrafting.

The present disclosure further provides an imaging lens module,including the aforementioned plastic lens barrel and an optical lensassembly, wherein the optical lens assembly is disposed in the plasticlens barrel. Therefore, it is favorable for improving the image qualityof the imaging lens module.

The imaging lens module can further include a retaining ring, whereinthe retaining ring is for fixing the optical lens assembly in theplastic lens barrel. Therefore, it is favorable for avoiding surfacereflection between lens elements when space of lens elements between theoptical lens elements changes.

The imaging lens module can further include a glue disposed between atleast one of the annular convex structures and the retaining ring.Therefore, it is favorable for accumulating the glue around theretaining ring with the annular convex structures having a reversed hookstructure, so that the glue would not easily overflow to the lenselements and contaminate the lens elements, and would not easilyoverflow to the outside of the plastic lens barrel to affect theappearance of the plastic lens barrel.

The annular convex structures can be not contacted with the optical lensassembly. Therefore, it is favorable for avoiding destroying the annularconvex structure during the assembling process of the optical lenselements so as to affect the expected effect.

Each of the aforementioned features of the plastic lens barrel and theimaging lens module can be utilized in various combinations forachieving the corresponding effects.

The present disclosure further provides an electronic device, includingthe aforementioned imaging lens module. Therefore, an electronic devicehaving both image quality and manufacturing stability can be provided.

According to the above embodiment, specific embodiments are set forthbelow and described in detail in conjunction with the drawings.

1st Embodiment

FIG. 1A is a schematic view of an imaging lens module 100 according tothe 1st embodiment of the present disclosure. FIG. 1B is an explodedview of the imaging lens module 100 according to the 1st embodiment inFIG. 1A. In FIG. 1A and FIG. 1B, the imaging lens module 100 includes aplastic lens barrel 110 and optical lens assembly (its reference numeralis omitted), wherein the optical lens assembly is disposed in theplastic lens barrel 110.

In detail, in the 1st embodiment, the optical lens assembly includes, inorder from the object side to the image side, six lens elements 121,122, 123, 124, 125, 126, and the imaging lens module 100 furtherincludes three retaining rings 131, 132, 133 for fixing the optical lensassembly in the plastic lens barrel 110. Moreover, the imaging lensmodule 100 can further include five light shielding sheets 141, 142,143, 144, 145, which can be respectively disposed between any twoadjacent lens elements or retaining rings. In the 1st embodiment, thedetailed arrangement of the retaining rings 131, 132, 133, and the lightshielding sheets 141, 142, 143, 144, 145 is as shown in FIG. 1A and FIG.1B, but will not be described in detail herein. The arrangement of thelens elements, the retaining rings and the light shielding sheets in theimaging lens module of the present disclosure is not limited to the 1stembodiment.

FIG. 1C is a planar cross-sectional view of the plastic lens barrel 110according to the 1st embodiment in FIG. 1A. FIG. 1D is athree-dimensional view of the plastic lens barrel 110 according to the1st embodiment in FIG. 1A. In FIG. 1C and FIG. 1D, the plastic lensbarrel 110 includes an object-end portion 111, an image-end portion 112,and a tube portion 113, wherein the tube portion 113 is connected to theobject-end portion 111 and the image-end portion 112. The object-endportion 111 has an object-end outer surface 1111, an object-end opening1113, and an object-end inner surface 1112, wherein one end of theobject-end inner surface 1112 is connected to the object-end outersurface 1111 and surrounds the object-end opening 1113. The image-endportion 112 has an image-end outer surface 1121 and an image-end opening1122. The tube portion 113 includes a plurality of the tube innersurfaces (its reference numeral is omitted), wherein one tube innersurface includes a plurality of the annular convex structures 1131, andeach of the annular convex structures 1131 surrounds the central axis Xof the plastic lens barrel 110. In the 1st embodiment, the annularconvex structures 1131 and the plastic lens barrel 110 are integrallyformed, and each of the annular convex structures 1131 has a smoothsurface. The annular convex structures 1131 are not contacted with theoptical lens assembly by the arrangement of the retaining ring 133.

Each of the annular convex structures 1131 includes a peak point 1131 aand two valley points (that is, 1132 a, 1132 b) through a cross sectionof the central axis X. The peak point 1131 a is the closest point to thecentral axis X on each of the annular convex structures 1131. Theprojecting positions of the two valley points on the central axis X arelocated on two sides of the projecting position of the peak point 1131 aon the central axis X, wherein the projecting positions of the twovalley points on the central axis X do not overlap with the projectingposition of the peak point 1131 a on the central axis X. In detail, eachof the projecting positions of the peak points 1131 a on the centralaxis X does not overlap with each of the projecting positions of thevalley points on the central axis X, and the two valley points of eachof the annular convex structures 1131 are farther from the central axisX than the peak point 1131 a of each of the annular convex structures1131 is thereto.

Moreover, please refer to FIG. 1C, the projecting positions of the twovalley points on an axis vertical to the central axis X do not overlapwith projecting position of the peak point 1131 a on the axis verticalto the central axis X; that is, projecting positions of the two valleypoints on an virtual line Y do not overlap with projecting position ofthe peak point 1131 a on the virtual line Y, and the virtual line Y isperpendicular to the central axis X.

A distance between the projecting position of one of the two valleypoints on the central axis X and the projecting position of the peakpoint 1131 a on the central axis X is different from a distance betweenthe projecting position of the other one of the two valley points on thecentral axis X and the projecting position of the peak point 1131 a onthe central axis X. In the 1st embodiment, the two valley points are afirst valley point 1132 a and a second valley point 1132 b,respectively. A distance between a projecting position of the firstvalley point 1132 a on the central axis X and the projecting position ofthe peak point 1131 a on the central axis X is larger than a distancebetween a projecting position of the second valley point 1132 b on thecentral axis X and the projecting position of the peak point 1131 a onthe central axis X.

Moreover, the peak point 1131 a of each of the annular convex structures1131 is gradually away from the central axis X from the object-endportion 111 to the image-end portion 112.

FIG. 1E is a schematic view of parameters d, and D according to the 1stembodiment. In FIG. 1C and FIG. 1E, when the distance between theprojecting position of the first valley point 1132 a on the central axisX and the projecting position of the peak point 1131 a on the centralaxis X is DG1, the distance between the projecting position of thesecond valley point 1132 b on the central axis X and the projectingposition of the peak point 1131 a on the central axis is DG2, a maximumdistance between the projecting position of each of the valley pointsand the projecting position of the peak point 1131 a on the axisvertical to the central axis X is HG (in the 1st embodiment, that is amaximum distance between the projecting position of the second valleypoint 1132 b and the projecting position of the peak point 1131 a on thevirtual line Y), the maximum opening diameter of the annular convexstructures 1131 is D, the minimum opening diameter of the annular convexstructures 1131 is d, and the elastic drafting ratio of the annularconvex structures 1131 is EDR(EDR=[(D−d)/D]×100%), the followingconditions of the Table 1 are satisfied, respectively.

TABLE 1 1st embodiment DG1 (mm) 0.0915 D(mm) 7.71 DG2 (mm) 0.0085 d(mm)7.6162 DG1/DG2 10.765 EDR (%) 1.217 HG (mm) 0.0246

FIG. 1F is a schematic view of molds 171, 172, and 173 in themanufacturing process of the plastic lens barrel 110 according to the1st embodiment. In FIG. 1F, the molds 171, 172, and 173 surround amolding injecting space 175, and an injecting channel 174 is formedbetween the mold 172 and the mold 173. During the molding process of theplastic lens barrel 110, the plastic material can be injected into themolding injecting space 175 along the direction 176 through theinjecting channel 174. The annular convex structures 1131 and theplastic lens barrel 110 can be integrally formed by the arrangement ofthe mold 171. The manufacturing molding method of the followingembodiments are the same as the manufacturing molding method of the 1stembodiment, and will not be described again.

2nd Embodiment

FIG. 2A is a schematic view of an imaging lens module 200 according tothe 2nd embodiment of the present disclosure. FIG. 2B is athree-dimensional view of the plastic lens barrel 210 according to the2nd embodiment in FIG. 2A. FIG. 2C is a planar cross-sectional view ofthe plastic lens barrel 210 according to the 2nd embodiment in FIG. 2A.As shown in FIG. 2A, the imaging lens module 200 includes a plastic lensbarrel 210 and optical lens assembly (its reference numeral is omitted),wherein the optical lens assembly is disposed in the plastic lens barrel210.

In detail, in the 2nd embodiment, the optical lens assembly includes, inorder from the object side to the image side, six lens elements 221,222, 223, 224, 225, 226, and the imaging lens module 200 furtherincludes three retaining rings 231, 232, 233 for fixing the optical lensassembly in the plastic lens barrel 210. Moreover, the imaging lensmodule 200 can further include five light shielding sheets (itsreference numeral is omitted), which can be respectively disposedbetween any two adjacent lens elements or retaining rings. In the 2ndembodiment, the detailed arrangement of the retaining rings 231, 232,233, and the light shielding sheet is shown in FIG. 2A, and the imaginglens module 200 can further include a glue 2331 disposed between theannular convex structure 2131 and the retaining ring 233. Thearrangement of the lens elements, the retaining rings and the lightshielding sheets in the imaging lens module of the present disclosure isnot limited to the 2nd embodiment.

As shown in FIG. 2C, the plastic lens barrel 210 includes an object-endportion 211, an image-end portion 212, and a tube portion 213, whereinthe tube portion 213 is connected to the object-end portion 211 and theimage-end portion 212. The object-end portion 211 has an object-endouter surface 2111, an object-end opening 2113, and an object-end innersurface 2112, wherein one end of the object-end inner surface 2112 isconnected to the object-end outer surface 2111 and surrounds theobject-end opening 2113. The image-end portion 212 has an image-endouter surface 2121 and an image-end opening 2122. The tube portion 213includes a plurality of the tube inner surfaces (its reference numeralis omitted), wherein one tube inner surface includes a plurality of theannular convex structures 2131, and each of the annular convexstructures 2131 surrounds the central axis X of the plastic lens barrel210. In the 2nd embodiment, the annular convex structures 2131 and theplastic lens barrel 210 are integrally formed, and each of the annularconvex structures 2131 has a smooth surface. The annular convexstructures 2131 are not contacted with the optical lens assembly by thearrangement of the retaining ring 233.

In FIG. 2A and FIG. 2B, each of the annular convex structures 2131includes a peak point 2131 a and two valley points (that is, 2132 a,2132 b) through a cross section of the central axis X. The peak point2131 a is the closest point to the central axis X on each of the annularconvex structures 2131. The projecting positions of the two valleypoints on the central axis X are located on two sides of the projectingposition of the peak point 2131 a on the central axis X, wherein theprojecting positions of the two valley points on the central axis X donot overlap with the projecting position of the peak point 2131 a on thecentral axis X. In detail, each of the projecting positions of the peakpoints 2131 a on the central axis X does not overlap with each of theprojecting positions of the valley points on the central axis X, and thetwo valley points of each of the annular convex structures 2131 arefarther from the central axis X than the peak point 2131 a of each ofthe annular convex structures 2131 is thereto.

Moreover, please refer to FIG. 2A, the projecting positions of the twovalley points on an axis vertical to the central axis X do not overlapwith projecting position of the peak point 2131 a on the axis verticalto the central axis X; that is, projecting positions of the two valleypoints on an virtual line Y do not overlap with projecting position ofthe peak point 2131 a on the virtual line Y, and the virtual line Y isperpendicular to the central axis X.

A distance between the projecting position of one of the two valleypoints on the central axis X and the projecting position of the peakpoint 2131 a on the central axis X is different from a distance betweenthe projecting position of the other one of the two valley points on thecentral axis X and the projecting position of the peak point 2131 a onthe central axis X. In the 2nd embodiment, the two valley points are afirst valley point 2132 a and a second valley point 2132 b,respectively. A distance between a projecting position of the firstvalley point 2132 a on the central axis X and the projecting position ofthe peak point 2131 a on the central axis X is larger than a distancebetween a projecting position of the second valley point 2132 b on thecentral axis X and the projecting position of the peak point 2131 a onthe central axis X.

Moreover, the peak point 2131 a of each of the annular convex structures2131 is gradually away from the central axis X from the object-endportion 211 to the image-end portion 212.

As shown in FIG. 2A and FIG. 2C, when the distance between theprojecting position of the first valley point 2132 a on the central axisX and the projecting position of the peak point 2131 a on the centralaxis X is DG1, the distance between the projecting position of thesecond valley point 2132 b on the central axis X and the projectingposition of the peak point 2131 a on the central axis is DG2, a maximumdistance between the projecting position of each of the valley pointsand the projecting position of the peak point 2131 a on the axisvertical to the central axis X is HG (in the 2nd embodiment, that is amaximum distance between the projecting position of the second valleypoint 2132 b and the projecting position of the peak point 2131 a on theaxis vertical to the central axis X), the maximum opening diameter ofthe annular convex structures 2131 is D, the minimum opening diameter ofthe annular convex structures 2131 is d, and the elastic drafting ratioof the annular convex structures 2131 is EDR(EDR=[(D−d)/D]×100%), thefollowing conditions of the Table 2 are satisfied, respectively.

TABLE 2 2nd embodiment DG1 (mm) 0.0638 D(mm) 7.71 DG2 (mm) 0.0085 d(mm)7.6162 DG1/DG2 7.506 EDR (%) 1.217 HG (mm) 0.0246

3rd Embodiment

FIG. 3A is a schematic view of an imaging lens module 300 according tothe 3rd embodiment of the present disclosure. FIG. 3B is athree-dimensional view of the plastic lens barrel 310 according to the3rd embodiment in FIG. 3A. FIG. 3C is a planar cross-sectional view ofthe plastic lens barrel 310 according to the 3rd embodiment in FIG. 3A.As shown in FIG. 3A, the imaging lens module 300 includes a plastic lensbarrel 310 and optical lens assembly (its reference numeral is omitted),wherein the optical lens assembly is disposed in the plastic lens barrel310.

In detail, in the 3rd embodiment, the optical lens assembly includes, inorder from the object side to the image side, six lens elements 321,322, 323, 324, 325, 326, and the imaging lens module 300 furtherincludes three retaining rings 331, 332, 333 for fixing the optical lensassembly in the plastic lens barrel 310. Moreover, the imaging lensmodule 300 can further include five light shielding sheets (itsreference numeral is omitted), which can be respectively disposedbetween any two adjacent lens elements or retaining rings. In the 3rdembodiment, the detailed arrangement of the retaining rings 331, 332,and 333, and the light shielding sheet is as shown in FIG. 3A, and theimaging lens module 300 can further include a glue 3331 disposed betweenthe annular convex structure 3131 and the retaining ring 333. Thearrangement of the lens elements, the retaining rings and the lightshielding sheets in the imaging lens module of the present disclosure isnot limited to the 3rd embodiment.

As shown in FIG. 3C, the plastic lens barrel 310 includes an object-endportion 311, an image-end portion 312, and a tube portion 313, whereinthe tube portion 313 is connected to the object-end portion 311 and theimage-end portion 312. The object-end portion 311 has an object-endouter surface 3111, an object-end opening 3113, and an object-end innersurface 3112, wherein one end of the object-end inner surface 3112 isconnected to the object-end outer surface 3111 and surrounds theobject-end opening 3113. The image-end portion 312 has an image-endouter surface 3121 and an image-end opening 3122. The tube portion 313includes a plurality of the tube inner surfaces (its reference numeralis omitted), wherein one tube inner surface includes a plurality of theannular convex structures 3131, and each of the annular convexstructures 3131 surrounds the central axis X of the plastic lens barrel310. In the 3rd embodiment, the annular convex structures 3131 and theplastic lens barrel 310 are integrally formed, and each of the annularconvex structures 3131 has a smooth surface. The annular convexstructures 3131 are not contacted with the optical lens assembly by thearrangement of the retaining ring 333.

In FIG. 3A and FIG. 3B, each of the annular convex structures 3131includes a peak point 3131 a and two valley points (that is, 3132 a,3132 b) through a cross section of the central axis X. The peak point3131 a is the closest point to the central axis X on each of the annularconvex structures 3131. The projecting positions of the two valleypoints on the central axis X are located on two sides of the projectingposition of the peak point 3131 a on the central axis X, wherein theprojecting positions of the two valley points on the central axis X donot overlap with the projecting position of the peak point 3131 a on thecentral axis X. In detail, each of the projecting positions of the peakpoints 3131 a on the central axis X does not overlap with each of theprojecting positions of the valley points on the central axis X, and thetwo valley points of each of the annular convex structures 3131 arefarther from the central axis X than the peak point 3131 a of each ofthe annular convex structures 3131 is thereto.

Moreover, please refer to FIG. 3A, the projecting positions of the twovalley points on an axis vertical to the central axis X do not overlapwith projecting position of the peak point 3131 a on the axis verticalto the central axis X; that is, projecting positions of the two valleypoints on an virtual line Y do not overlap with projecting position ofthe peak point 3131 a on the virtual line Y, and the virtual line Y isperpendicular to the central axis X.

A distance between the projecting position of one of the two valleypoints on the central axis X and the projecting position of the peakpoint 3131 a on the central axis X is different from a distance betweenthe projecting position of the other one of the two valley points on thecentral axis X and the projecting position of the peak point 3131 a onthe central axis X. In the 3rd embodiment, the two valley points are afirst valley point 3132 a and a second valley point 3132 b,respectively. A distance between a projecting position of the firstvalley point 3132 a on the central axis X and the projecting position ofthe peak point 3131 a on the central axis X is larger than a distancebetween a projecting position of the second valley point 3132 b on thecentral axis X and the projecting position of the peak point 3131 a onthe central axis X.

Moreover, the peak point 3131 a of each of the annular convex structures3131 is gradually away from the central axis X from the object-endportion 311 to the image-end portion 312.

As shown in FIG. 3A and FIG. 3C, when the distance between theprojecting position of the first valley point 3132 a on the central axisX and the projecting position of the peak point 3131 a on the centralaxis X is DG1, the distance between the projecting position of thesecond valley point 3132 b on the central axis X and the projectingposition of the peak point 3131 a on the central axis is DG2, a maximumdistance between the projecting position of each of the valley pointsand the projecting position of the peak point 3131 a on the axisvertical to the central axis X is HG (in the 3rd embodiment, that is amaximum distance between the projecting position of the second valleypoint 3132 b and the projecting position of the peak point 3131 a on theaxis vertical to the central axis X), the maximum opening diameter ofthe annular convex structures 3131 is D, the minimum opening diameter ofthe annular convex structures 3131 is d, and the elastic drafting ratioof the annular convex structures 3131 is EDR(EDR=[(D−d)/D]×100%), thefollowing conditions of the Table 3 are satisfied, respectively.

TABLE 3 3rd embodiment DG1 (mm) 0.0915 D(mm) 7.71 DG2 (mm) 0.0085 d(mm)7.6162 DG1/DG2 10.765 EDR (%) 1.217 HG (mm) 0.0246

4th Embodiment

FIG. 4A is a schematic view of an imaging lens module 400 according tothe 4th embodiment of the present disclosure. FIG. 4B is a planarcross-sectional view of the plastic lens barrel 410 according to the 4thembodiment in FIG. 4A. As shown in FIG. 4A, the imaging lens module 400includes a plastic lens barrel 410 and optical lens assembly (itsreference numeral is omitted), wherein the optical lens assembly isdisposed in the plastic lens barrel 410.

In detail, in the 4th embodiment, the optical lens assembly includes, inorder from the object side to the image side, six lens elements 421,422, 423, 424, 425, 426, and the imaging lens module 400 furtherincludes three retaining rings 431, 432, 433 for fixing the optical lensassembly in the plastic lens barrel 410. Moreover, the imaging lensmodule 400 can further include five light shielding sheets (itsreference numeral is omitted), which can be respectively disposedbetween any two adjacent lens elements or retaining rings. In the 4thembodiment, the detailed arrangement of the retaining rings 431, 432,433, and the light shielding sheet is as shown in FIG. 4A. Thearrangement of the lens elements, the retaining rings and the lightshielding sheets in the imaging lens module of the present disclosure isnot limited to the 4th embodiment.

As shown in FIG. 4B, the plastic lens barrel 410 includes an object-endportion 411, an image-end portion 412, and a tube portion 413, whereinthe tube portion 413 is connected to the object-end portion 411 and theimage-end portion 412. The object-end portion 411 has an object-endouter surface 4111, an object-end opening 4113, and an object-end innersurface 4112, wherein one end of the object-end inner surface 4112 isconnected to the object-end outer surface 4111 and surrounds theobject-end opening 4113. The image-end portion 412 has an image-endouter surface 4121 and an image-end opening 4122. The tube portion 413includes a plurality of the tube inner surfaces (its reference numeralis omitted), wherein one tube inner surface includes a plurality of theannular convex structures 4131, and each of the annular convexstructures 4131 surrounds the central axis X of the plastic lens barrel410. In the 4th embodiment, the annular convex structures 4131 and theplastic lens barrel 410 are integrally formed, and each of the annularconvex structures 4131 has a smooth surface. The annular convexstructures 4131 are not contacted with the optical lens assembly by thearrangement of the retaining ring 433.

In FIG. 4A and FIG. 4B, each of the annular convex structures 4131includes a peak point 4131 a and two valley points (that is, 4132 a,4132 b) through a cross section of the central axis X. The peak point4131 a is the closest point to the central axis X on each of the annularconvex structures 4131. The projecting positions of the two valleypoints on the central axis X are located on two sides of the projectingposition of the peak point 4131 a on the central axis X, wherein theprojecting positions of the two valley points on the central axis X donot overlap with the projecting position of the peak point 4131 a on thecentral axis X. In detail, each of the projecting positions of the peakpoints 4131 a on the central axis X does not overlap with each of theprojecting positions of the valley points on the central axis X, and thetwo valley points of each of the annular convex structures 4131 arefarther from the central axis X than the peak point 4131 a of each ofthe annular convex structures 4131 is thereto.

Moreover, please refer to FIG. 4A, the projecting positions of the twovalley points on an axis vertical to the central axis X do not overlapwith projecting position of the peak point 4131 a on the axis verticalto the central axis X; that is, projecting positions of the two valleypoints on an virtual line Y do not overlap with projecting position ofthe peak point 4131 a on the virtual line Y, and the virtual line Y isperpendicular to the central axis X.

A distance between the projecting position of one of the two valleypoints on the central axis X and the projecting position of the peakpoint 4131 a on the central axis X is different from a distance betweenthe projecting position of the other one of the two valley points on thecentral axis X and the projecting position of the peak point 4131 a onthe central axis X. In the 4th embodiment, the two valley points are afirst valley point 4132 a and a second valley point 4132 b,respectively. A distance between a projecting position of the firstvalley point 4132 a on the central axis X and the projecting position ofthe peak point 4131 a on the central axis X is larger than a distancebetween a projecting position of the second valley point 4132 b on thecentral axis X and the projecting position of the peak point 4131 a onthe central axis X.

Moreover, the peak point 4131 a of each of the annular convex structures4131 is gradually away from the central axis X from the object-endportion 411 to the image-end portion 412.

As shown in FIG. 4A and FIG. 4B, when the distance between theprojecting position of the first valley point 4132 a on the central axisX and the projecting position of the peak point 4131 a on the centralaxis X is DG1, the distance between the projecting position of thesecond valley point 4132 b on the central axis X and the projectingposition of the peak point 4131 a on the central axis is DG2, a maximumdistance between the projecting position of each of the valley pointsand the projecting position of the peak point 4131 a on the axisvertical to the central axis X is HG (in the 4th embodiment, that is amaximum distance between the projecting position of the second valleypoint 4132 b and the projecting position of the peak point 4131 a on theaxis vertical to the central axis X), the maximum opening diameter ofthe annular convex structures 4131 is D, the minimum opening diameter ofthe annular convex structures 4131 is d, and the elastic drafting ratioof the annular convex structures 4131 is EDR(EDR=[(D−d)/D]×100%), thefollowing conditions of the Table 4 are satisfied, respectively.

TABLE 4 4th embodiment DG1 (mm) 0.0789 D(mm) 7.86 DG2 (mm) 0.0238 d(mm)7.5569 DG1/DG2 3.315 EDR (%) 3.856 HG (mm) 0.0635

5th Embodiment

FIG. 5A is a schematic view of an imaging lens module according to the5th embodiment of the present disclosure. FIG. 5B is a planarcross-sectional view of a plastic lens barrel 510 according to the 5thembodiment in FIG. 5A. As shown in FIG. 5A, the imaging lens module 500includes a plastic lens barrel 510 and optical lens assembly (itsreference numeral is omitted), wherein the optical lens assembly isdisposed in the plastic lens barrel 510.

In detail, in the 5th embodiment, the optical lens assembly includes, inorder from the object side to the image side, five lens elements 521,522, 523, 524, 525, and the imaging lens module 500 further includes tworetaining rings 531, 532 for fixing the optical lens assembly in theplastic lens barrel 510. Moreover, the imaging lens module 500 canfurther include four light shielding sheets (its reference numeral isomitted), which can be respectively disposed between any two adjacentlens elements or retaining rings. In the 5th embodiment, the detailedarrangement of the retaining rings 531, 532 and the light shieldingsheet is as shown in FIG. 5A. The arrangement of the lens elements, theretaining rings and the light shielding sheets in the imaging lensmodule of the present disclosure is not limited to the 5th embodiment.

As shown in FIG. 5B, the plastic lens barrel 510 includes an object-endportion 511, an image-end portion 512, and a tube portion 513, whereinthe tube portion 513 is connected to the object-end portion 511 and theimage-end portion 512. The object-end portion 511 has an object-endouter surface 5111, an object-end opening 5113, and an object-end innersurface 5112, wherein one end of the object-end inner surface 5112 isconnected to the object-end outer surface 5111 and surrounds theobject-end opening 5113. The image-end portion 512 has an image-endouter surface 5121 and an image-end opening 5122. The tube portion 513includes a plurality of the tube inner surfaces (its reference numeralis omitted). In the 5th embodiment, the object-end inner surface 5112includes a plurality of annular convex structures 5114, and each of theannular convex structures 5114 surrounds the central axis X of theplastic lens barrel 510. The annular convex structures 5114 and theplastic lens barrel 510 are integrally formed, and each of the annularconvex structures 5114 has a smooth surface. The annular convexstructures 5114 are not contacted with the optical lens assembly by thearrangement of the retaining ring 531.

In FIG. 5A and FIG. 5B, each of the annular convex structures 5114includes a peak point 5115 and two valley points (that is, 5114 a, 5114b) through a cross section of the central axis X. The peak point 5115 isthe closest point to the central axis X on each of the annular convexstructures 5114. The projecting positions of the two valley points onthe central axis X are located on two sides of the projecting positionof the peak point 5115 on the central axis X, wherein the projectingpositions of the two valley points on the central axis X do not overlapwith the projecting position of the peak point 5115 on the central axisX. In detail, each of the projecting positions of the peak points 5115on the central axis X does not overlap with each of the projectingpositions of the valley points on the central axis X, and the two valleypoints of each of the annular convex structures 5114 are farther fromthe central axis X than the peak point 5115 of each of the annularconvex structures 5114 is thereto.

Moreover, please refer to FIG. 5A, the projecting positions of the twovalley points on an axis vertical to the central axis X do not overlapwith projecting position of the peak point 5115 on the axis vertical tothe central axis X; that is, projecting positions of the two valleypoints on an virtual line Y do not overlap with projecting position ofthe peak point 5115 on the virtual line Y, and the virtual line Y isperpendicular to the central axis X.

A distance between the projecting position of one of the two valleypoints on the central axis X and the projecting position of the peakpoint 5115 on the central axis X is different from a distance betweenthe projecting position of the other one of the two valley points on thecentral axis X and the projecting position of the peak point 5115 on thecentral axis X. In the 5th embodiment, the two valley points are a firstvalley point 5114 a and a second valley point 5114 b, respectively. Adistance between a projecting position of the first valley point 5114 aon the central axis X and the projecting position of the peak point 5115on the central axis X is larger than a distance between a projectingposition of the second valley point 5114 b on the central axis X and theprojecting position of the peak point 5115 on the central axis X.

Moreover, the peak point 5115 of each of the annular convex structures5114 is gradually away from the central axis X from the image-endportion 512 to the object-end portion 511.

As shown in FIG. 5A and FIG. 5B, when the distance between theprojecting position of the first valley point 5114 a on the central axisX and the projecting position of the peak point 5115 on the central axisX is DG1, the distance between the projecting position of the secondvalley point 5114 b on the central axis X and the projecting position ofthe peak point 5115 on the central axis is DG2, a maximum distancebetween the projecting position of each of the valley points and theprojecting position of the peak point 5115 on the axis vertical to thecentral axis X is HG (in the 5th embodiment, that is a maximum distancebetween the projecting position of the second valley point 5114 b andthe projecting position of the peak point 5115 on the axis vertical tothe central axis X), the maximum opening diameter of the annular convexstructures 5114 is D, the minimum opening diameter of the annular convexstructures 5114 is d, and the elastic drafting ratio of the annularconvex structures 5114 is EDR(EDR=[(D−d)/D]×100%), the followingconditions of the Table 5 are satisfied, respectively.

TABLE 5 5th embodiment DG1 (mm) 0.0789 D(mm) 5.06 DG2 (mm) 0.0238 d(mm)4.757 DG1/DG2 3.315 EDR (%) 5.988 HG (mm) 0.0635

6th Embodiment

FIG. 6A is a schematic view of an appearance of an electronic deviceaccording to the 6th embodiment of the present disclosure. FIG. 6B isanother schematic view of the appearance of the electronic deviceaccording to the 6th embodiment in FIG. 6A. FIG. 6C is a component viewof the electronic device 600 according to the 6th embodiment in FIG. 6A.FIG. 6D is a block diagram of the electronic device 600 according to the6th embodiment in FIG. 6A. As shown in FIG. 6A, FIG. 6B, FIG. 6C, andFIG. 6D, the electronic device 600 is a smart phone according to the 6thembodiment. The electronic device 600 includes a camera module 610according to the present disclosure, wherein the camera module 610includes an imaging lens module 611 of any one of the aforementionedembodiments and an image sensor 612, the image sensor 612 is disposed onan image surface (not shown) of the imaging lens module 611. Therefore,it is favorable for satisfying requirements of the mass production andappearance of the imaging lens module applied to the electronic devicenowadays.

Specifically, the user activates the capturing mode by the userinterface 680 of the electronic device 600, wherein the user interfaceof the 6th embodiment can be a touch screen 680 a, a button 680 b, etc.At this moment, the imaging lens module 611 collects imaging light onthe image sensor 612 and outputs electronic signals associated withimages to an image signal processor (ISP) 670.

Corresponding to the camera specifications of the electronic device 600,the electronic device 600 can further include an optical anti-shakemechanism 640, which can be OIS anti-shake feedback device, moreover,the electronic device 600 can further include at least one auxiliaryoptical component (its reference numeral is omitted) and at least onesensing component 650. In the 6th embodiment, the auxiliary opticalcomponent can be a flash module 661 and a focusing assisting module 662,the flash module 661 can be for compensating color temperature, thefocusing assisting module 662 can be an infrared distance measurementcomponent, and a laser focus module, etc. The sensing component 650 canhave functions for sensing physical momentum and kinetic energy, such asan accelerator, a gyroscope, a Hall Effect Element, to sense shaking orjitters applied by hands of the user or external environments. Further,it is favorable for obtaining good image quality with arrangement of theautofocus function and the optical anti-shake component 640 of thecamera module 610 of the electronic device 600. Furthermore, theelectronic device 600 can have a capturing function with multiple modes,such as taking optimized selfies, high dynamic range (HDR) under a lowlight condition, 4K resolution recording, etc. Additionally, the usercan visually see the captured image of the camera through the touchscreen and manually operate the view finding range on the touch screento achieve the autofocus function of what you see is what you get.

Moreover, in FIG. 6C, the camera module 610, the optical anti-shakecomponent 640, the sensing component 650, the flash module 661, and thefocusing assisting module 662 can be disposed on a flexible printedcircuitboard (FPC) 690 a and electrically connected with the associatedelements, such as an imaging signal processing element 670, via aconnector 690 b to perform a capturing process. Since the currentelectronic devices, such as smartphones, have a tendency of being lightand thin, the way of firstly disposing the camera module, the imaginglens assembly and related elements on the flexible printed circuitboardand secondly integrating the circuit into the main board of theelectronic device via the connector can satisfy the mechanical design ofthe limited space inside the electronic device and the layoutrequirements and obtain more margins. The auto focus function of theimaging lens module can be controlled more flexibly via the touch screenof the electronic device. In other embodiments (not shown), the sensingelements and the auxiliary optical elements can also be disposed on themain board of the electronic device or carrier boards in other formsaccording to requirements of the mechanical design and the circuitlayout.

Furthermore, the electronic device 600 can further include, but not belimited to, a display, a control unit, a storage unit, a random accessmemory, a read-only memory, or the combination thereof.

7th Embodiment

FIG. 7 is a schematic view of an electronic device 700 according to the7th embodiment of the present disclosure. In FIG. 7 , the electronicdevice 700 is a smart phone according to the 7th embodiment, and theelectronic device 700 includes three camera modules 710, 720, and 730,the flash module 740, the auxiliary focusing component 750, the imagingsignal processing element 760, the user interface (not shown), and imagesoftware processor (not shown), wherein the camera modules 710, 720 and730 face towards the same side (that is, the object side). When the usercaptures the subject through the user interface, the electronic device700 gathers the light and collects the image by using the camera modules710, 720, and 730, activates the flash module 740 to fill light,conducts fast focusing by using the object distance information of thesubject provided by the focusing assisting module 750, and processes theimage optimization with the imaging signal processing element 760 andthe image software processor, so as to further improve the image qualityproduced by the imaging lens module in the camera modules 710, 720, and730. Moreover, the focusing assisting module 750 can use infrared orlaser auxiliary focusing component to achieve fast focus. The userinterface can be touch screen or physical capturing button, and theimage processing software can be used for capturing image and processingimage.

In the 7th embodiment, the camera modules 710, 720, and 730 canrespectively include any of the imaging lens modules of theaforementioned 1st to 5th embodiments, and are not limited thereto.

In addition, in the 7th embodiment, an optical anti-shake mechanism 711is disposed on the outer side of the camera module 710, which can be anOIS anti-shake feedback device. The image capturing device 730 is atelescope lens assembly, but the disclosure is not limited thereto.

8th Embodiment

FIG. 8 is a schematic view of an electronic device 800 according to the8th embodiment of the present disclosure. The electronic device 800 ofthe 8th embodiment is a tablet, and the electronic device 800 includes acamera module 810, wherein the camera module 810 includes an imaginglens module (not shown) and an image sensor according to the disclosure,and the image sensor is disposed on the image surface of the imaginglens module (not shown).

9th Embodiment

FIG. 9 is a schematic view of an electronic device 900 according to the9th embodiment of the present disclosure. The electronic device 900 ofthe 9th embodiment is a wearable device, and the electronic device 900includes a camera module 910, wherein the camera module 910 includes animaging lens module (not shown) and an image sensor (not shown)according to the disclosure, and the image sensor is disposed on theimage surface of the imaging lens module (not shown).

The foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. It is to be noted thatTables show different data of the different embodiments; however, thedata of the different embodiments are obtained from experiments. Theembodiments were chosen and described in order to best explain theprinciples of the disclosure and its practical applications, to therebyenable others skilled in the art to best utilize the disclosure andvarious embodiments with various modifications as are suited to theparticular use contemplated. The embodiments depicted above and theappended drawings are exemplary and are not intended to be exhaustive orto limit the scope of the present disclosure to the precise formsdisclosed. Many modifications and variations are possible in view of theabove teachings.

What is claimed is:
 1. A plastic lens barrel, comprising: an object-end portion having an object-end outer surface, an object-end opening, and an object-end inner surface, wherein one end of the object-end inner surface is connected to the object-end outer surface and surrounds the object-end opening; an image-end portion having an image-end outer surface and an image-end opening; and a tube portion connecting the object-end portion and the image-end portion, and comprising a plurality of tube inner surfaces, wherein at least one of the tube inner surfaces and the object-end inner surface comprises a plurality of annular convex structures, each of the annular convex structures surrounds a central axis of the plastic lens barrel, and a cross-sectional plane of each of the annular convex structures passing through the central axis comprises: a peak point being a closest point to the central axis on each of the annular convex structures; and two valley points, wherein projecting positions of the two valley points on the central axis are located on two sides of a projecting position of the peak point on the central axis, and the projecting positions of the two valley points on the central axis do not overlap with the projecting position of the peak point on the central axis; wherein the two valley points are a first valley point and a second valley point, respectively, and a distance between a projecting position of the first valley point on the central axis and the projecting position of the peak point on the central axis is larger than a distance between a projecting position of the second valley point on the central axis and the projecting position of the peak point on the central axis; wherein the distance between the projecting position of the first valley point on the central axis and the projecting position of the peak point on the central axis is DG1, the distance between the projecting position of the second valley point on the central axis and the projecting position of the peak point on the central axis is DG2, and the following condition is satisfied: 1.1<DG1/DG2<25.0.
 2. The plastic lens barrel of claim 1, wherein the annular convex structures and the plastic lens barrel are integrally formed.
 3. The plastic lens barrel of claim 2, wherein each of the projecting positions of the peak points on the central axis does not overlap with each of the projecting positions of the valley points on the central axis.
 4. The plastic lens barrel of claim 2, wherein the projecting positions of the two valley points on an axis vertical to the central axis do not overlap with the projecting position of the peak point on the axis vertical to the central axis.
 5. The plastic lens barrel of claim 2, wherein a distance between the projecting position of one of the two valley points on the central axis and the projecting position of the peak point on the central axis is different from a distance between the projecting position of the other one of the two valley points on the central axis and the projecting position of the peak point on the central axis.
 6. The plastic lens barrel of claim 2, wherein the distance between the projecting position of the first valley point on the central axis and the projecting position of the peak point on the central axis is DG1, the distance between the projecting position of the second valley point on the central axis and the projecting position of the peak point on the central axis is DG2, and the following condition is satisfied: 1.8<DG1/DG2<17.0.
 7. The plastic lens barrel of claim 2, wherein each of the annular convex structures has a smooth surface.
 8. The plastic lens barrel of claim 2, wherein a maximum opening diameter of the annular convex structures is D, a minimum opening diameter of the annular convex structures is d, an elastic drafting ratio of the annular convex structures is EDR, and the following condition is satisfied: 0%<EDR<8%, wherein EDR=[(D−d)/D]×100%.
 9. The plastic lens barrel of claim 2, wherein the two valley points of each of the annular convex structures are farther from the central axis than the peak point of each of the annular convex structures is thereto.
 10. The plastic lens barrel of claim 2, wherein the peak point of each of the annular convex structures is gradually away from the central axis from the object-end portion to the image-end portion or from the image-end portion to the object-end portion.
 11. The plastic lens barrel of claim 4, wherein in each of the annular convex structures, a maximum distance between the projecting position of each of the valley points and the projecting position of the peak point on the axis vertical to the central axis is HG, and the following condition is satisfied: 0.002 mm<HG<0.15 mm.
 12. An imaging lens module, comprising: the plastic lens barrel of claim 1; and an optical lens assembly disposed in the plastic lens barrel.
 13. The imaging lens module of claim 12, further comprising: a retaining ring for fixing the optical lens assembly in the plastic lens barrel.
 14. The imaging lens module of claim 13, further comprising: a glue disposed between at least one of the annular convex structures and the retaining ring.
 15. The imaging lens module of claim 12, wherein the annular convex structures are not contacted with the optical lens assembly.
 16. An electronic device, comprising: the imaging lens module of claim
 12. 